Transfer device for mail and the like

ABSTRACT

A transfer device is provided which includes a rotating paddle wheel (FR) whose preferably fixedly arranged paddles (F) form pockets (Z) which receive the items (S) arriving on a first conveying device (FE1) and discharge the items onto circulating item carriers (ST) of a second conveying device (FE2), the speed (v1) and the spacing (t1) of the incoming items (S), the circumferential speed (u) and the circumferential spacing (t2) of the paddle wheel (FR) and the speed (v3) and the spacing (t3) of the circulating item carriers (ST) being matched to one another. Direct transportation of the items (S) into the pockets (Z) of the paddle wheel (FR) is made possible by segmenting each of the paddles (F) by a plurality of gaps arranged one behind the other in the axial direction, and by interleaving guided segments of the first conveying device (FE1) into the paddle wheel (FR) in the region of the gaps. The transfer of the items (S) to the pockets (Z) can thus be reliably controlled since an ejection operation which is dependent on shape and mass of the items (S) may be eliminated.

BACKGROUND OF THE INVENTION

The present invention generally relates to a sorting or transfer devicefor moving items such as letters, postcards, packets and the like. Moreparticularly, the present invention relates to an axially-segmentedpaddle wheel arrangement which is interleaved with a multibelt firstconveying device. The paddle wheel receives items delivered from thefirst conveying device and deposits the items in a predetermined manneron a second conveying device.

The machine-readable post codes which should be specified on items ofmail, such as letters, postcards, packets and the like, as anidentification for a postal location permit rapid, mechanicaldistribution of mail. In this arrangement, for example according to U.S.Pat. No. 3,031,062, sorting of the incoming items of mail takes placewith the aid of controllable item carriers which are each loaded with anitem of mail in special input locations and then discharge said item ofmail to a sorting containing, or a corresponding sorting compartment,corresponding the respective post code. Since the sorting containers orsorting compartments may be arranged in various levels, the itemcarriers circulating on conveying devices must, if appropriate, also becapable of spanning various levels. After transfer of the item of themail to the assigned sorting container or the assigned sortingcompartment, the empty item carriers can then once again be loaded withitems of mail when they pass an input location. When the mail istransferred to the abovedescribed sorting apparatus, the items of mailarriving on a conveying device, e.g. a belt conveyor, have to bedischarged in a specific manner and, preferably, individually to theitem carriers, which pass at relatively high speed.

It is known from GB-A-2 101 066 to provide the paddle wheel with gaps orslots in the paddles, the gaps being spaced along the axial directionand to guide segments of a conveying device into the pockets of thepaddle wheel in the region of the gaps.

SUMMARY OF THE INVENTION

The present invention provides an improved sorting or transfer apparatusof a type which is particularly suitable for mail sorting operations.

In an embodiment, the transfer device includes a rotatable paddle wheelwith a plurality of axially-aligned paddles between which are defined aplurality of pockets. Each of the paddles has a plurality ofradially-extending segments spaced from each other by a plurality ofrespective gaps. Collectively, these gaps form concentric gaps in thepaddle wheel, segmenting the paddle wheel into a plurality ofaxially-spaced segments. The transfer device also includes a firstconveying device which has a plurality of parallel, spaced, endlessbelts which wrap over a center of said paddle wheel within therespective gaps between the radially extending paddle segments. Thepaddle wheel is thereby rotatable with the belts in an interleavedmanner. The center of the paddle wheel preferably has a plurality ofdeflection wheels arranged at its center within the gaps, providing afriction surface for the belts of the first conveyor to wind over thepaddle wheel axle.

The first conveying device delivers items into the pockets of saidpaddle wheel. A speed and the spacing of the items on the firstconveying device are matched to a circumferential speed of the paddlewheel and the spacing of the pockets.

In an embodiment, a second conveying device is arranged under the paddlewheel for receiving items discharged from the paddle wheel. The secondconveying device has a plurality of circulating receptacles forreceiving items discharged from the pockets of the paddle wheel. Thesereceptacles may be provided in grouped sections which are linkedtogether. The speed of the second conveying device and spacing of thereceptacles of the second conveying device are matched to thecircumferential speed of the paddle wheel so that items are properlydispensed in an intended receptacle from a one of the pockets.

In an embodiment, the transfer device includes a first conveying device,a second conveying device with a plurality of circulating item carriers,and a rotatable paddle wheel. The paddle wheel has a plurality ofpaddles defining a plurality of pockets for receiving items arriving onthe first conveying device and discharging the items onto thecirculating item carriers of the second conveying device. A speed andthe spacing of the incoming items on the first conveying device arematched to a circumferential speed and angular spacing of pockets on thepaddle wheel, which are matched to a speed and spacing of thecirculating item carriers. Each paddle of the paddle wheel is segmentedby a plurality of gaps arranged one behind the other in the axialdirection. Cooperatively spaced segments of the first conveying deviceare guided into the pockets of the paddle wheel in the region of thegaps, and the segments of the first conveying device are guided aroundcoaxially and rotatably arranged deflection wheels of the paddle wheel.

In an embodiment, the paddles are aligned tangentially with respect to acircle which runs concentrically with the wheel axle of the paddlewheel.

In an embodiment, the paddle wheel includes at least one additionalpaddle. The additional paddle, with an adjacent one of the paddles,defines a void corresponding to regularly occurring void spaces betweentwo groups of item carriers of the second conveying device. This holdsan item within a smaller pocket in the paddle wheel to ensure that theitem is not dispensed in a space which separates linked groups.

In an embodiment, the transfer device also includes a third or furtherconveying device arranged to feed the items onto the first conveyingdevice. The further conveying device also has a plurality of spaced,parallel, endless belts. At one end of the further conveying device, itsbelts are positioned to interleave with the belts at a portion of thefirst conveying device, forming an overlapping delivery path so thatitems are moved from the further conveyor onto the first conveyor, forcontinued movement to the paddle wheel. For a smooth transition betweenconveyors, the belts of the further conveying device are guided beneatha common conveying plane of the first conveying device and of thefurther conveying device.

In an embodiment, the paddle wheel and the first conveying device aredriven by a common motor.

In an embodiment, guide means are provided for guiding items in thepaddle wheel pockets tangentially along said paddle wheel upstream ofthe second conveying device. Preferably, this guide means is acirculating belt positioned to run generally tangentially to a portionof the paddle wheel at a speed corresponding to the tangential speed ofthe paddle wheel.

The invention is based on the problem of providing a transfer device formail which is of a simple construction and by means of which the mailarriving on a conveying device can be discharged in a reliable manneronto circulating item carriers of a sorting apparatus.

Besides transferring mail to a sorting apparatus, the transfer deviceaccording to the invention may also be used for comparable tasks. Forexample, the inventive system may be used in storage systems orautomated order-picking systems, in the case of which coded itemsarriving on a first conveying device and are to be transferred to itemcarriers of a second conveying device.

The invention is based on the finding that a paddle wheel withpreferably fixedly arranged paddles, on the one hand, makes it possiblefor the items arriving on a first conveying device to be receivedreliably, and that, on the other hand, specific transfer of the items tothe individual item carriers is also ensured by the circumferentialspeed and circumferential spacing of the paddle wheel being matched tothe speed and spacing of the circulating item carriers. For the incomingitems to be received reliably in the individual pockets of the paddlewheel, all that is necessary is for the speed and spacing of theincoming items to be matched to the circumferential speed andcircumferential spacing of the paddle wheel.

A cooperatively-alternating segmentation of paddle wheel and firstconveying device allows an interleaved, overlapping sort of operationwhich; permits direct transportation of the items into the pockets ofthe paddle wheel. The transfer of the items from the first conveyingdevice to the pockets of the paddle wheel can thus be reliablycontrolled since, in particular, an ejection operation which isdependent on the shape and mass of the items can be dispensed with.

The guidance of the segments around the coaxially and rotatably arrangeddeflection wheels makes it possible for the items to be transportedreliably as far as the rear end of the jaw-like pockets of the paddlewheel. The guidance of the segments of the first conveying device viadeflection wheels of the paddle wheel, however, necessitates a higherdegree of maintenance than does an embodiment in which the firstconveying device has segments which project freely into the pockets ofthe paddle wheel.

An advantageous embodiment of the invention provides a parallelalignment of paddles and first conveying device in the transfer region,with the result that the items can be raised in parallel from theconveying device in an extremely careful manner by the respectivepaddle. Moreover, the tangential alignment of the paddles permitsadaptation of the pockets in the transfer region to an inclination ofthe circulating item carriers, and thus particularly reliable transferof the items to the circulating item carriers.

The additional paddles according to an aspect of the inventionadvantageously permit matching and adaptation of the paddle wheel to thespacing between the item carriers even if gaps are present betweenindividual groups of item carriers. Such gaps result, for example, whena plurality of item carriers are provided on circulating carriages ofthe second conveying device.

A preferred configuration of the invention permits transportation of theitems on the further conveying device at a predetermined spacing as wellas transfer of the items to the first conveying device while thisspacing is maintained. The spacing of the items can be predetermined,for example, by transversely aligned studs of the further conveyingdevice, the studs then retracting downwards in the region of transfer tothe first conveying device. Bending or other forms of mechanicalimpairment of the items by the studs in the region of the pockets of thepaddle wheel is thus avoided.

In an embodiment,the invention provides an advantage of permanentlymatching the speed of the incoming items to the circumferential speed ofthe paddle wheel.

The guide means according an embodiment of the invention reliablyprevent the items from dropping from the pockets in that circumferentialregion of the paddle wheel which is located upstream of the dischargeregion. If the guide means are formed, by an endlessly circulating belt,then the risk of mechanical impairment of the items can be reliablyruled out since the belt runs along automatically and at the same speed.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the detailed description of thepreferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic side view of a transfer device for items which isequipped with a paddle wheel,

FIG. 2 is a schematic side view of the transfer device according to FIG.1 with a common drive for paddle wheel and incoming conveying device,and

FIG. 3 is a view onto the face of a slotted paddle showing thesegmentation of the paddle wheel and the incoming conveying device beingguided into the pockets of the paddle wheel.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a considerably simplified schematic representation of atransfer device for items. Said transfer device comprises a rotatingpaddle wheel FR whose paddles F, arranged fixedly around the wheel axleRA indicated by a cross, form sector-like pockets Z which receive theitems arriving on a first conveying device FE1 and discharge said itemsonto circulating item carriers ST of a second conveying device FE2.

The items S, indicated by chain-dotted lines, are, for example, letters,which are fed from above, at three feed locations, onto a furtherconveying device FEW, indicated merely by a chain-dotted line. Fromthere, the items S are then transferred to the first conveying deviceFE1 and transported directly into a pocket Z of the paddle wheel FR. Onrotation of the paddle wheel FR in the direction of rotation DR, anendless belt EB then initially prevents the items S from dropping fromthe pockets Z. The endless belt EB, guided via a total of three rollersRO, is driven in a frictionally locking manner by the paddle wheel FR,as a result of which an undesired relative movement between the endlessbelt EB and the items S is avoided. Downstream of the endless belt EB,the items S then drop from the pockets Z in the discharge region intothe assigned item carriers ST of the second conveying device FE2. Thealignment, tangential with respect to an imaginary inner circle of thepaddle wheel FR, of the paddles F permits adaptation to the inclinationof the item carriers ST in the transfer region.

The item carriers ST of the second conveying device FE2 are componentsof a sorting apparatus for mail, the construction and mode of operationof which are described, for example, in earlier patent applications P 4323 564.6 and 43 23 565.4.

The speed v1 and the spacing t1 of the items S arriving on the furtherconveying device FEW and the first conveying device FE1, thecircumferential speed u and the circumferential spacing t2 of the paddlewheel FR and the speed v3 and the spacing t3 of the circulating itemcarriers ST are matched to one another such that constantly reliabletransfer of the items S is always ensured. The speed v1 and the spacingt1 of the incoming items S are selected such that the next empty pocketZ in each case of the paddle wheel FR circulating at constant angularspeeds can be loaded. The circumferential spacing t2 of the paddles F ofthe paddle wheel FR and the spacing t3 of the item carriers ST arematched to one another in the same way as the spacings of a gear wheeland rack which engage with one another. In addition, however, thecircumferential speed u of the paddle wheel FR and the speed v3 of theitem carriers ST still have to be matched to one another such that thehorizontal components of these speeds are the same and the depictedarrangement of the circumferential spacing t2 of the pockets Z in thecircumferential region with respect to the spacing t3 of the itemcarriers ST remains intact.

It can also be seen from FIG. 1 that in each case four item carriers STare combined in a group, for example a carriage, and that there is a gapL2 between in each case two groups of item carriers ST. For this reason,the paddle wheel FR is equipped with fixedly arranged additional paddlesZF which each form, with the trailing paddle F, as seen in the directionof rotation DR, empty pockets LZ which are assigned to theabovementioned gaps L2 between two groups of item carriers ST. It isalso necessary during loading of the further conveying device FEW withitems S for the gaps L2 and the empty pockets LZ to be taken intoaccount in that, after four feed operations in each case, the spacing t1is increased by a corresponding compensatory amount Δt.

It can be seen from FIG. 1 that the items S are transported, via thefirst conveying device FE1, directly into the pockets Z of the paddlewheel FR. This transportation into the rotating paddle wheel FR is madepossible by segmentation of paddle wheel FR and first conveying deviceFE1, and FIG.3 is referred to for details of this. In the case of thesegmentation of the paddle wheel FR, which rotates on a shaft W, theindividual paddles F exhibit a plurality of gaps arranged one behind theother, as seen in the direction of the wheel axle RA. In the region ofthe gaps L1, deflection wheels designated by UR are arranged rotatablyon the shaft W, the segments, designated by SG1, of the first conveyingdevice being guided around said deflection wheels. The further guidanceof the endlessly circulating segments SG1, formed, for example, by flatbelts, takes place via a tensioning roller SR and deflection rollersUR01 and UR02. The individual segments of the further conveying deviceFEW, indicated in FIG. 1 merely by a chain-dotted line, are also guidedvia said deflection rollers UR01 and UR02.

The drive of the paddle wheel FR, of the first conveying device FE1 andof the further conveying device FEW can be seen from FIG. 2. A commonmotor M drives the shaft W (see FIG. 3) of the paddle wheel FR via afirst drive wheel AR1, a belt RI1, indicated by a chain-dotted line, anda wheel RD. Moreover, the motor M drives the deflection roller URO1 viabelt RI2, represented by chain-dotted lines, which deflection roller,for its part, drives the tensioning roller SR via a further belt RI3,represented by chain-dotted lines. This drive via the common motor M, onthe one hand, ensures that the first conveying device FE1 and thefurther conveying device FEW are always driven at the same speed v1,and, on the other hand, also ensures that the ratio of this speed v1 tothe circumferential speed u or the angular speed of the paddle wheel FRalways remains intact.

The guidance of the further conveying device FEW, which is subdividedinto segments SG2, via the two deflection rollers URO1 and UR02 permitsfriction-free transfer of the items S (see FIG. 1) to the firstconveying device FE1. It is particularly advantageous here that thetransverse studs, which belong to the segments SG2, and are notrepresented in any more detail in the drawings, but are necessary formaintaining the spacing t1 (see FIG. 1), retract downwards out of thecommon conveying plane of the conveying devices FE1 and FEW. Thisretraction of the transverse studs prevents them from bending the itemsS (see FIG. 1) in the pockets Z of the paddle wheel FR and possiblydamaging them.

In the exemplary embodiment represented, the items S (see FIG. 1) arriveat speeds v1=2.15 m/s and at a spacing t1=340 mm. The spacing t1Δt is510 mm. The paddle wheel FR, which rotates at 20.8 revolutions perminute, has sixteen pockets Z and four empty pockets LZ. Thecircumferential spacing t2 of the paddle wheel FR is approximately 127mm. The spacing t3 of the item carriers ST, which rotate at a speedv3=0.625 m/s, is 100 mm, while the gap L2 between two groups of itemcarriers ST is 50 mm in each case. The segmentation, indicated in FIG.3, of paddle wheel FR and first conveying device FE1 comprises a totalof ten segments of the paddle wheel FR and nine segments SG1 of thefirst conveying device SE1.

Various changes and modifications to the presently preferred embodimentswill be apparent to those skilled in the art. Such changes andmodifications may be made without departing from the spirit and scope ofthe present invention and without diminishing its attendant advantages.Therefore, the appended claims are intended to cover such changes andmodifications.

What is claimed is:
 1. A transfer device for transferring items, thedevice comprising:a first conveying device; a second conveying devicehaving a plurality of circulating item carriers; and a rotatable paddlewheel with a plurality of paddles defining a plurality of pockets toreceive items arriving on the first conveying device and discharge saiditems onto circulating item carriers of the second conveying device;wherein a speed and the spacing of the incoming items on the firstconveying device are matched to a circumferential speed andcircumferential spacing of the paddle wheel, which are matched to aspeed and spacing of the circulating item carriers; and wherein eachpaddle of the paddle wheel is segmented by a plurality of gaps arrangedone behind the other in the axial direction, wherein cooperativelyspaced segments of the first conveying device are guided into thepockets of the paddle wheel in the region of the gaps, and wherein thesegments of the first conveying device are guided around coaxially androtatably arranged deflection wheels of the paddle wheel.
 2. Thetransfer device as claimed in claim 1, wherein the paddles are alignedtangentially with respect to a circle which runs concentrically with thewheel axle of the paddle wheel.
 3. The transfer device as claimed inclaim 1, wherein the paddle wheel includes one or more fixedly arrangedadditional paddles to form, together with a trailing paddles, emptypockets respective voids which correspond to regularly occurring voidspaces between two groups of item carriers of the second conveyingdevice.
 4. The transfer device as claimed in claim 1, further comprisinga further conveying device arranged upstream of the first conveyingdevice, the further conveying device also being subdivided intosegments, wherein downstream of a transfer location, the segments of thefurther conveying device are guided beneath a common conveying plane ofthe first conveying device and of the further conveying device.
 5. Thetransfer device as claimed in claim 1, wherein the paddle wheel and thefirst conveying device are driven by a common motor.
 6. The transferdevice as claimed in claim 1, further comprising guide means for guidingthe items along a circumferential region of the paddle wheel upstream ofa location of transfer of the items to the second conveying device. 7.The transfer device as claimed in claim 6, wherein the guide means areformed by an endlessly circulating belt.
 8. A device for transferringitems, the device comprising:a rotatable paddle wheel with a pluralityof axially-aligned paddles between which are defined a plurality ofpockets, each said paddle having a plurality of radially-extendingsegments spaced from each other by a plurality of respective gaps; and afirst conveying device including a plurality of parallel, spaced,endless belts which wrap over a center of said paddle wheel within therespective gaps between the radially extending paddle segments, thefirst conveying device delivering items into said pockets of said paddlewheel; wherein a speed and the spacing of the items on the firstconveying device are matched to a circumferential speed of the paddlewheel and the spacing of the pockets.
 9. The device according to claim8, further comprising:a second conveying device disposed under saidpaddle wheel for receiving items discharged from said paddle wheel, thesecond conveying device having a plurality of circulating receptaclesfor receiving items discharged from the pockets of the paddle wheel;wherein the speed of the second conveying device and spacing of thereceptacles of the second conveying device are matched to thecircumferential speed of the paddle wheel.
 10. The transfer device asclaimed in claim 8, wherein the paddle wheel includes at least oneadditional paddle defining, with an adjacent paddle, a respective voidcorresponding to regularly occurring void spaces between two groups ofitem carriers of the second conveying device.
 11. The transfer device asclaimed in claim 8, further comprising:a further conveying devicearranged to feed said items onto the first conveying device, the furtherconveying device also including a plurality of spaced, parallel, endlessbelts which are positioned to interleaf with the belts at a portion ofthe first conveying device, the belts of the further conveying devicebeing guided beneath a common conveying plane of the first conveyingdevice and of the further conveying device.
 12. The transfer device asclaimed in claim 8, wherein the paddle wheel and the first conveyingdevice are driven by a common motor.
 13. The transfer device as claimedin claim 8, further comprising:guide means for guiding items in saidpaddle wheel pockets tangentially along said paddle wheel upstream ofthe second conveying device.
 14. The transfer device as claimed in claim13, wherein said guide means includes a circulating belt positioned torun generally tangentially to a portion of the paddle wheel at a speedcorresponding to the tangential speed of the paddle wheel.
 15. Atransfer device for conveying and sorting items, the device comprising:apaddle wheel having a plurality of paddles between which are definedrespective pockets, the paddle wheel having a plurality of segmentsseparated by a plurality of concentric gaps formed collectively in thepaddles; and a first conveying device having a plurality of parallelbelts spaced to run within said concentric gaps between said segments asthe belts wrap over a center of the paddle wheel, so that the paddlewheel is rotatable with the belts in an interleaved manner.
 16. Thetransfer device according to claim 15, wherein the speed of the firstconveying device and a spacing of items on the first conveyingcorresponds to a paddle wheel dimensioning and its rotational speed suchthat one item is delivered into each pocket.
 17. The transfer deviceaccording to claim 15, further comprising:a second conveying devicehaving a plurality of circulating item carriers arranged to respectivelyreceive dispensed items from said pockets; wherein the second conveyingdevice is disposed below the paddle wheel has a speed corresponding to atangential speed of the paddle wheel.
 18. The transfer device accordingto claim 15, further comprising a further conveying device comprising aplurality of parallel belts arranged at an upstream end of the firstconveying device, the belts of the further conveying device being spacedto alternatingly fit between the belts of the first conveying device sothat the items are delivered from the further conveying device onto thefirst conveying device.
 19. The transporting device according to claim15, further comprising a guide to hold items in the pockets prior totheir dispensing into the item carriers.
 20. The transporting deviceaccording to claim 19, wherein the guide is an endless belt having aportion disposed generally tangentially along the paddle wheel, the belthaving a speed corresponding to a tangential speed of the paddle wheel.